Abstract

Production models form one of the two groups of models used in studying fish
population and assessing the state of the fish stocks. Unlike the analytical models,
they do not consider the events within a
population, and particularly ignore the
growth and mortality of the individuals
forming the population. These models view
population as one unit of biomass, with all
individuals having the same growth and
mortality rates. The surplus production
models deal with the entire stock, the entire
fishing effort and the total yield obtained
from the stock, without entering into any
details such as the growth and mortality
parameters or the effect of the mesh size on
the age of fish capture etc. Surplus
production models were introduced by
Graham (1935), but they are often referred
to as Schaefer-models.